The present invention is an improved magnetic head suspension (HSA) for use with dynamic magnetic storage devices or rigid disk drives. More specifically, it is a head suspension assembly (HSA) that has improved gimbal, beam, and attachment structures to improve dynamic performance of the HSA, decrease pitch and roll stiffnesses, increase lateral and in plane stiffnesses, improve manufacturability, and improve head bond location.
Conventionally available magnetic head suspension assemblies for rigid disk drives allow magnetic read write heads to pitch about a first axis and roll about a second axis orthogonal to the first axis when imperfections in the disk drive assembly tend to place the heads in improper positions. The present invention is designed to allow significant reductions in the pitch and roll stiffness of the head suspension assembly, thus allowing the heads to easily maintain proper attitude. At the same time, the present invention is designed to increase the stiffness in the direction of rotation to maintain proper head position with respect to the suspension assembly. Further, the invention is designed to resist permanent distortion caused by forces in all directions.
Conventional head suspension assemblies consist of a head support baseplate, load beam, and flexure which are usually etched, stamped and then welded together. The present invention is designed to allow the flexure and/or the baseplate to be an integral part of the load beam, which reduces manufacturing steps and improves the ability to manufacture the head suspension with the proper head position and attitude.
Conventional head suspension attachments or base plates are welded to the load beam and attached to an actuator arm and are generally configured for swage or screw attachment. The present invention allows the attachment to be an integral part of the load beam and not welded, which reduces process steps, eases disk drive assembly, and improves the ability to position the head properly with respect to the actuator arm. The present invention attaches to the actuator arm by an attachment means employing an interference fit such as a clip.
Another embodiment of the present invention is designed to attach the load beam to the actuator arm by a shrink fit interference means encircling the arm and load beam(s). Such a shrink fit could be performed by heating the attachment means to expand and then contract or heating the attachment to simply contract it around the arm and load beam(s), which reduces the number of components and process steps and allows the head suspension assembly to be attached and removed from the actuator arm easily.
Conventional means for positioning and aligning the read write head to the suspension assembly when attaching the head suspension assembly to the actuator arm when attaching it to place a pin through a hole in the load beam, a pin through a hole(s) in the baseplate, and mount the baseplate on the arm with screws or with the baseplate boss. The present invention is designed to improve the accuracy and ease of positioning the head with respect to the suspension assembly and to facilitate the alignment of the head suspension assembly with respect to the actuator arm by using a pin through a hole in the load beam and a pin through a slot at the base end. The pin/hole registration will keep the part aligned in the x and y directions while the pin/slot registration keeps the part from rotating about the z axis. Further, a unitary suspension piece eliminates the tolerance build up from welding three components together and allows the head location to depend solely on the precision manufacture of the holes and slots.
Conventionally available magnetic head suspension assemblies have load beams with rails formed away from the rigid disk or toward the rigid disk, as shown in commonly assigned application Ser. No. 07/583,048 and with a form line that is generally parallel to the disk surface.
In the prior art, the conventional rail formed to project from the surface of the load beam which is oriented away from the disk offered increased clearance between the disk and the load beam for lifting the load beam, while the conventional rail oriented toward the disk surface offered increased clearance between two back to back head suspension assemblies and allows for closer disk spacing. The present invention is designed to offer increased clearance on both sides of the head suspension assembly for lifting the load beam and allowing closer disk spacing. The invention uses a rail form line that is not parallel to the disk surface but is closer to the disk at the slider end and away from the disk at the base end such that the lift clearance can be maximized near the base and the disk spacing clearance can be maximized near the slider.